1. Technical Field
The present disclosure relates to a screen having a reflectivity, which causes diffuse reflection of an image projected by a projector, and a transparency, which allows transmission of a background.
2. Description of the Related Art
Recent years have seen some proposals for a transparent screen that displays an image by diffusely reflecting an image projected by a projector while providing a transparency, which allows transmission of a background. For example, an image display system including such a transparent screen superimposes an image on a night view and displays it on the transparent screen mounted on a window of a high-rise building, or presents an image as if it were displayed in the air at a live performance or the like. As noted above, the transparent screen is expected to serve as a key device for realizing a new image expression using the projector.
Systems of projecting an image using a projector include a back projecting system that projects an image from a back side of a screen to display the image as a transmitted image and a front projecting system that projects an image from a front side of the screen to display the image as a reflected image. The screen for the back projecting system is referred to as a transmission-type screen, and the screen for the front projecting system is referred to as a reflection-type screen. The transparent screen that transmits a background can be used as both of these transmission-type screen and reflection-type screen.
As an example of the transparent screen, a transmission-type transparent screen including a scattering layer has been proposed (see Japanese Unexamined Patent Application Publications No. 2011-113068 and No. 2015-212800). This scattering layer is formed by dispersing a trace amount of specific diffusing particulates in a transparent body. The transmission-type transparent screen having this configuration allows the scattering layer to greatly diffuse an image projected by a projector so as to display the image as well as transmits a background rectilinearly. Furthermore, in the transmission-type transparent screen having this configuration, light diffused by the scattering layer is partially reflected by an interface between a back surface of the transmission-type transparent screen and the air. Thus, the transmission-type transparent screen can also display an image as a reflected image similarly to the screen of the front projecting system. Accordingly, the transmission-type transparent screen may be sometimes applied to a window of a commercial facility as the reflection-type transparent screen.
Moreover, as the reflection-type transparent screen, proposed is a screen that is obtained by forming on a plurality of protrusions a selective reflection layer that selectively reflects right circularly polarized laser light or left circularly polarized laser light with a specific wavelength, and coating a surface of the selective reflection layer with a transparent material (see Japanese Unexamined Patent Application Publication No. 2014-071250). This screen can not only display the projected laser light as an image but also transmit a background because it rectilinearly transmits light other than polarized light with a specific wavelength.